Believe it or not, humans have been obsessed with sand way longer than you might think. Picture our earliest ancestors stepping onto a beach or riverbank and feeling that squishy, gritty stuff underfoot. Maybe they paused, realizing this wasn't just dirt - it was a tiny, ever-shifting world beneath their toes. Sand was like nature's version of glitter: impossible to ignore and guaranteed to stick around, even if you didn't want it to. Fast forward a few million years and it's clear: sand is basically childhood's best friend. No matter where you grew up, chances are you've built a sandcastle or two - or maybe a sand mountain that looked a bit more like a lopsided molehill. These fleeting masterpieces teach kids everything about building, patience, and the heartbreak of tides. Seriously, if you think adults deal with disappointment, try explaining to a five-year-old why their castle just vanished.